frame.writeByte(Http2.TYPE_HEADERS)
    frame.writeByte(FLAG_END_HEADERS or FLAG_END_STREAM)
    frame.writeInt(expectedStreamId and 0x7fffffff)
    frame.writeAll(headerBytes)

    // Check writer sends the same bytes.
    assertThat(sendHeaderFrames(true, sentHeaders)).isEqualTo(frame)
    reader.nextFrame(
      requireSettings = false,
      object : BaseTestHandler() {
        override fun headers(

        - '!pyproject.toml'

internal:
  - all:
    - changed-files:
      - any-glob-to-any-file:
        - .github/**
        - scripts/**
        - .gitignore
        - .pre-commit-config.yaml
        - pdm_build.py
        - requirements*.txt
        - docs/en/data/sponsors.yml
        - docs/en/overrides/main.html
      - all-globs-to-all-files:
        - '!docs/*/docs/**'
        - '!fastapi/**'

        CacheBuilder.newBuilder()
            .expireAfterAccess(500000, MILLISECONDS)
            .maximumSize(count)
            .build();
  }

  public void testComputeIfAbsent() {
    // simultaneous insertion for same key, expect 1 winner
    doParallelCacheOp(
        count,
        n -> {
          cache.asMap().computeIfAbsent(key, k -> "value" + n);
        });
    assertEquals(1, cache.size());
  }

/**
 * A bimap (or "bidirectional map") is a map that preserves the uniqueness of its values as well as
 * that of its keys. This constraint enables bimaps to support an "inverse view", which is another
 * bimap containing the same entries as this bimap but with reversed keys and values.
 *
 * <h3>Implementations</h3>
 *
 * <ul>
 *   <li>{@link ImmutableBiMap}
 *   <li>{@link HashBiMap}
 *   <li>{@link EnumBiMap}

   * exactly one entry for each distinct element in the multiset (thus it always has the same size
   * as the {@link #elementSet}). The order of the elements in the element set is unspecified.
   *
   * <p>The entry set is backed by the same data as the multiset, so any change to either is
   * immediately reflected in the other. However, multiset changes may or may not be reflected in

        assertNotNull(result, "Unwrapped tree should not be null");
        assertSame(customTree, result, "Should return the same custom tree instance");
        verify(smbTree).unwrap(CustomSmbTree.class);
    }

    /**
     * Test for unwrap() method with the same type.
     * Verifies that unwrap can return itself when the type matches.
     */
    @Test
    void testUnwrap_withSameType() {

 * need for a distinct {@code ImmutableBiMultimap} type.
 *
 * <p><a id="iteration"></a>
 *
 * <p><b>Key-grouped iteration.</b> All view collections follow the same iteration order. In all
 * current implementations, the iteration order always keeps multiple entries with the same key
 * together. Any creation method that would customarily respect insertion order (such as {@link

 * with the range (if any) that contains a specified key.
 *
 * <p>In contrast to {@link RangeSet}, no "coalescing" is done of {@linkplain
 * Range#isConnected(Range) connected} ranges, even if they are mapped to the same value.
 *
 * @author Louis Wasserman
 * @since 14.0
 */
@SuppressWarnings("rawtypes") // https://github.com/google/guava/issues/989
@DoNotMock("Use ImmutableRangeMap or TreeRangeMap")
@GwtIncompatible

## Read the Tutorial first { #read-the-tutorial-first }

The next sections assume you already read the main [Tutorial - User Guide: Security](../../tutorial/security/index.md){.internal-link target=_blank}.

# GraphQL { #graphql }

As **FastAPI** is based on the **ASGI** standard, it's very easy to integrate any **GraphQL** library also compatible with ASGI.

You can combine normal FastAPI *path operations* with GraphQL on the same application.

/// tip

**GraphQL** solves some very specific use cases.

It has **advantages** and **disadvantages** when compared to common **web APIs**.